Firearm indexing mechanism

ABSTRACT

A revolver includes a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having more than six chambers, each of the chambers adapted to receive a cartridge, wherein the cylinder is rotatable into discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the discrete firing positions.

FIELD OF THE INVENTION

The present invention relates to firearms, and more particularly to an indexing mechanism for firearms.

BACKGROUND

A single action revolver usually includes a hammer actuated by the user to produce rotation of a cylinder containing cartridges discharged by the revolver. In such a revolver, firing is caused by a subsequent and distinct movement of the index finger of the hand that pulls the trigger after the hammer has been actuated into a full cock position.

Single action revolvers typically have a revolving cylinder that holds a number of cartridges to be discharged by the firearm during use. Such cylinders allow for easy loading, firing, and unloading of the revolver and give the user the ability to fire multiple rounds before having to reload the cylinder. The capacity of the revolving cylinder dictates the available rounds for firing by the user before reloading and a typical revolver has a revolving cylinder with six chambers, each chamber adapted to hold a single cartridge. A cylinder having more than six chambers would allow the revolver to hold additional cartridges and thereby allow a user to discharge more cartridges before having to reload the cylinder. In addition to being able to hold additional cartridges, if the cylinder had substantially the same diameter as a standard six-chamber cylinder, it could be used with a frame of a standard sized revolver. However, if the cylinder with additional chambers were oversized, a larger frame might be required.

SUMMARY OF THE INVENTION

According to aspects of the present invention, a revolver is provided including a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having twelve chambers, each of the twelve chambers adapted to receive a cartridge, wherein the cylinder is rotatable into twelve discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the discrete firing positions.

In one embodiment, the pawl has a single finger adapted to contact the cylinder and the cylinder is configured to rotate about 30 degrees between discrete firing positions. More specifically, in one embodiment, rotation of the hammer from a safety position in which the trigger tang is in the second notch to a full cock position in which the trigger sear engages the hammer sear causes the cylinder to rotate 30 degrees. Further, each of the twelve chambers may be adapted to receive a .22 caliber cartridge. Additionally, a ratchet may be attached to the cylinder to engage the pawl, and the ratchet may comprise twelve teeth.

In another embodiment, a revolver is provided including a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having a plurality of chambers, each of the plurality of chambers adapted to receive a cartridge, wherein the cylinder is rotatable into discrete firing positions; and a pawl connected to the hammer for rotating the cylinder thirty degrees between the discrete firing positions.

In one embodiment, the pawl has a single finger adapted to contact the cylinder and is adapted to contact the cylinder at only a single point.

In yet another embodiment, a revolver is provided including a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having more than six chambers, each of the more than six chambers adapted to receive a cartridge, wherein the cylinder is rotatable into a plurality of discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the discrete firing positions, wherein the pawl has a single finger adapted to contact the cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portion of a revolver having a cylinder according to an embodiment of the present invention.

FIG. 2 is a left side partial sectional view of the revolver of FIG. 1 with the hammer in an at rest position.

FIG. 3 is a right side partial sectional view of the revolver of FIG. 1 with the hammer in the at rest position.

FIGS. 4, 5 and 6 are left side, rear and right side partial views, respectively, of an indexing mechanism of the revolver of FIG. 1 with the hammer in an at rest position.

FIGS. 7, 8, and 9 are left side, rear and right side partial views, respectively, of an indexing mechanism of the revolver of FIG. 1 with the hammer in the safety position.

FIGS. 10, 11 and 12 are left side, rear and right side partial views, respectively, of an indexing mechanism of the revolver of FIG. 1 with the hammer in a loading position.

FIGS. 13, 14 and 15 are left side, rear and right side partial views, respectively, of an indexing mechanism of the revolver of FIG. 1 with the hammer in an intermediate position.

FIGS. 16, 17 and 18 are left side, rear and right side partial views, respectively, of an indexing mechanism of the revolver of FIG. 1 with the hammer in a full cock position.

DETAILED DESCRIPTION OF THE INVENTION

In general, embodiments of the present invention are directed to providing a single action revolver having an indexing and firing mechanism including a rotatable cylinder that can accommodate more than six cartridges within the cylinder and having a diameter with substantially the same diameter as a standard six-cartridge cylinder. Therefore, the indexing and firing mechanism is configured to be incorporated into a frame designed for a standard six-cartridge single action revolver. Additionally, the firing action, i.e., pulling back the hammer into a full cock position and then pulling the trigger to discharge a cartridge from the cylinder, is substantially similar to a standard single action revolver. In one embodiment, the cylinder is configured to hold twelve cartridges and can be housed within the frame of a standard six-cylinder revolver such as the COLT® .45 revolver.

With reference to FIG. 1, a single action revolver 10 includes a frame 12 and a cylinder 14 rotatably mounted within the frame by a cylinder pin removably attached to the frame. The cylinder 14 includes a plurality of cartridge chambers 16, in this case, twelve, and a ratchet 18 secured to the rear face of the cylinder for rotating the cylinder between the discrete firing positions thereof. In one embodiment, the ratchet has twelve teeth in a configuration to allow the cylinder to rotate thirty degrees in accordance with operation of the indexing mechanism, as described in more detail below.

A recess 20 is defined on the right side of the frame 12 so that each of the cartridge chambers 16 can be aligned with the recess to permit the loading of unused cartridges and the ejection of spent cartridges. A gate 22 is configured to be lodged within the recess 20 and is pivoted on the frame 12 such that it can be moved between the open position, as shown in FIG. 1, to permit the successive insertion of cartridges into the cartridge chambers 16 as the cylinder is turned, and the closed position to prevent the cartridges from becoming dislodged from the cylinder during operation of the revolver. The revolver 10 may also include an ejector rod mounted along a barrel for ejecting spent cartridges from the cartridge chambers 16. In one embodiment, the cartridge chambers 16 are dimensioned to hold .22 caliber cartridges. However, it will be appreciated that the cartridge chambers could be dimensioned to hold other caliber cartridges as well.

A hammer 24 is pivotally attached to the frame 12 by a screw 36 (FIG. 2) and is biased toward the fired position by a leaf spring 26 mounted in the grip 28 of the frame. As will be described in more detail below with respect to operation of the indexing mechanism, the hammer 24 is configured to be rotated in a cycle from a safety position to a loading position and then to a full cock position via an intermediate or bolt drop and lockup position. A firing pin 29 is carried by the face of the hammer 24 such that the firing pin may pass through an aperture 30 in the frame to strike a cartridge in a respective cartridge chamber 16 in the cylinder 14 aligned with the aperture in the firing position. As will be appreciated, if the cartridge chamber 16 is misaligned with respect to the aperture 30, the cartridge may be improperly discharged or not discharged at all.

With reference now to FIGS. 2 and 3, a drive pawl or hand 32 is configured to engage the teeth 19 of the ratchet 18 to rotate the cylinder 14. The pawl 32 is spring urged against the ratchet 18 by a leaf spring 33 and is connected at its lower end to the base of the hammer 24 by a boss or integral stud which is inserted into the side of the hammer. The pawl 32, unlike a conventional two-step pawl, has only a single “finger” 68 extending integrally from a lower portion of the pawl. The finger 68 is oriented and dimensioned to engage a single tooth 19 of the ratchet 18 for rotating the ratchet, and thereby the cylinder, between discrete firing positions, as described in more detail below. The pawl 32 also has a recess 70 for containing a bent lower extremity of the leaf spring 33.

The base of the hammer 24 is further configured to interact with a trigger 38 which may be actuated by a user to discharge a cartridge from the chamber 16. In one embodiment, the base of the hammer 24 includes a first notch 40 defined by a lip 42, and a hammer sear 44. The first notch 40 serves as a loading notch to maintain the hammer 24 in a loading position in which the cylinder 14 is unlocked so that it may be freely rotated during the insertion of cartridges into the chambers 16.

The base of the hammer 24 further includes a second notch 46 similar to the first notch 40 and located above the first notch closer to the firing pin 29, as shown in FIG. 2. The second notch 46 functions to ensure that the hammer 24 will not return to the fired position should it be released before a trigger tang 48 is positioned under the loading notch, as described below. It will be appreciated that although a hammer 24 having a particular configuration is described with respect to the present embodiment, embodiments of the present invention are not limited to hammers having this particular configuration, but rather may be used with hammers having a variety of configurations.

The trigger 38 is pivotally mounted on a trigger screw 52 secured to the frame 12 and extending transversely thereto. The trigger tang 48 terminates in a trigger sear 50, wherein the trigger tang is configured to be received in the second notch 46 to hold the hammer in the safety position and in the first notch 40 to hold the hammer in the loading position, and the trigger sear 50 is configured to be received in the hammer sear 44 to retain the hammer in the full cock position. A sloping surface 54 on the trigger 38 is contacted by a first leg of a bifurcated leaf spring 56 to bias trigger rotation in a clockwise direction as shown in FIG. 2 until a force to overcome the bias is applied by a user.

A cylinder lock 58 is pivotally attached to the frame 12 for engaging the cylinder 14 to prevent rotation of the cylinder when the hammer is in certain positions (i.e., any position other than the loading position). More specifically, a second leg of the bifurcated leaf spring 56 biases the cylinder lock 58 about a mounting pin 60 such that a projection 62 on the cylinder lock is urged into one of a plurality of circumferentially spaced locking notches 64 on a periphery of the cylinder 14. In one embodiment, the cylinder 14 has twelve notches 64, one notch corresponding to each of the twelve cartridge chambers 16. A tail 66 of the cylinder lock 58 is contacted by a protrusion 68 on the hammer 24 for moving the cylinder lock between a locking and an unlocking position with respect to the cylinder 14.

Operation of the indexing mechanism will now be described with respect to FIGS. 4-18. The operation of the indexing mechanism results in rotation of the cylinder between discrete firing positions, i.e., the cylinder is rotated from an orientation wherein a first cartridge chamber 16 is aligned with the aperture 30 to an orientation wherein a second cartridge chamber adjacent the first cartridge chamber is aligned with the aperture. As described in more detail below, operation of the indexing mechanism for embodiments of the present invention has a similar “feel” to operation of an indexing mechanism of a traditional six-shot single action revolver even though the operation of the mechanism is different from the traditional six-shot single action revolver. With reference to these figures, the angular movement of a reference ratchet tooth 19 will be described with respect to an imaginary horizon line extending through a center of the cylinder 14 to indicate the amount of rotation of the cylinder 14 during operation of the indexing mechanism. As will be appreciated, for a cylinder 14 having twelve cartridge chambers 16, the cylinder will rotate thirty degrees from an orientation in which a first chamber is aligned with the aperture 30 in a firing position, to an orientation in which a successive chamber adjacent the first chamber is aligned with the aperture.

With reference now to FIGS. 4-6, the indexing mechanism is shown in the at rest position in which the trigger tang 48 rests against a side surface of the lower portion of the hammer 24 and the firing pin 29 may be proximate or within the aperture 30. In this position, with particular reference to FIG. 5, the reference ratchet tooth 19 extends along an axis at about negative 10 degrees from the horizon extending through a center of the ratchet 18 and the cylinder lock 58 engages a notch 64 of the cylinder to prevent rotation of the cylinder.

As shown in FIGS. 7-9, the hammer 24 is rotated such that trigger tang 48 is engaged with the second notch 46 in the safety position. As in the at rest position, the reference ratchet tooth 19 extends along an axis at about negative 10 degrees from the horizon extending through a center of the ratchet 18, as shown in FIG. 8. Additionally, the cylinder lock 58 continues to engage the notch 64 of the cylinder 14 in this position.

From the safety position, the hammer 24 can be rotated rearwardly away from the cylinder to the loading position, as shown in FIGS. 10-12, wherein the trigger tang 48 is inserted into and maintained within the first notch 40. When the hammer 24 is moved from the safety position to the loading position, the movement of the hammer causes the pawl 32 to engage the reference ratchet tooth 19 and rotate the cylinder about 15 degrees in the clockwise direction as shown in FIG. 11. In the loading position, the cylinder lock 58 is disengaged from the cylinder 14 so that the cylinder is freely rotatable, allowing a user to insert cartridges into each of the cartridge chambers 16. Although the cylinder 14 is freely rotatable in the loading position, it will be understood that when the finger 68 of the pawl 32 is engaged with the reference ratchet tooth 19 in the loading position, the reference ratchet tooth extends along an axis of about five degrees from the horizon.

With reference now to FIGS. 13-15, the hammer 24 can be rotated from the loading position to an intermediate or bolt drop and lockup position to attain the full thirty degree rotation to align the successive cartridge chamber 16 with the aperture 30. As shown in the figures, with the end of the pawl 32 still engaging the reference ratchet tooth 19, the hammer 24 is moved further rearwardly such that the pawl rotates the cylinder 14 an additional ten degrees from its orientation on the loading position in the clockwise direction as shown in FIG. 14. As such, the cylinder 14 can be rotated between discrete firing positions with the pawl 32 contacting only a single tooth 19 of the ratchet 18. Additionally, rotation of the hammer 24 causes the cylinder lock 58 to rotate back into engagement with a respective locking notch 64 on the cylinder 14 to prevent further rotation of the cylinder. As will be appreciated, in the intermediate position the trigger tang 48 is between the first notch 40 and the trigger sear 50, and therefore, the hammer is not able to necessarily be maintained in the intermediate position by the trigger 38. However, the intermediate position is described as the point when the cylinder has been rotated thirty degrees from the safety position by the pawl 32 such that a successive cartridge chamber 16 is aligned with the aperture 30, wherein the pawl 32 is still in contact with the tooth 19 of the ratchet 18, and wherein the cylinder lock 58 is engaged with a locking notch 64.

With reference now to FIGS. 16-19, the hammer 24 can be further rotated from the intermediate position to the full cock position in which the trigger sear 50 engages the hammer sear 44 and in which the revolver 10 is ready to be fired. As the hammer is moved from the intermediate position to the full cock position, the pawl 32 disengages from the ratchet 18 entirely, although the pawl continues to move upward (with respect to FIGS. 16-19) as the hammer rotates. Accordingly, the hammer can be rotated all the way to the full cock position, yet the pawl 32 only rotates the cylinder thirty degrees rather than sixty degrees required for a six-shot cylinder.

If a user of the revolver does not want to fire the revolver after the hammer 24 is rotated into the full cock position, the user may disengage the trigger sear 50 from the hammer sear 44 and slowly rotate the hammer 24 back toward the cylinder 14 until the trigger tang 48 is inserted into the first notch 40.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention. 

1. A revolver comprising: a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having twelve chambers, each of the twelve chambers adapted to receive a cartridge, wherein the cylinder is rotatable into twelve discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the discrete firing positions.
 2. The revolver of claim 1, wherein the pawl has a single finger adapted to contact the cylinder.
 3. The revolver of claim 1, wherein each of the twelve chambers is adapted to receive a .22 caliber cartridge.
 4. The revolver of claim 1, wherein the cylinder is configured to rotate about 30 degrees between discrete firing positions.
 5. The revolver of claim 1, further comprising a ratchet on the cylinder, wherein the pawl engages the ratchet to rotate the cylinder.
 6. The revolver of claim 1, wherein the ratchet comprises twelve teeth.
 7. The revolver of claim 1, wherein the hammer has a first notch and a second notch adapted to receive a trigger tang integral with the trigger, and a hammer sear adapted to receive a trigger sear integral with the trigger tang.
 8. The revolver of claim of claim 7, wherein rotation of the hammer from a safety position in which the trigger tang is in the second notch to a full cock position in which the trigger sear engages the hammer sear causes the cylinder to rotate 30 degrees.
 9. The revolver of claim of 1, further comprising a cylinder lock pivotally mounted to the frame and adapted to engage the cylinder to prevent rotation of the cylinder.
 10. The revolver of claim 9, wherein the cylinder has twelve notches and wherein the cylinder lock is adapted to engage one of the twelve notches in each discrete firing position.
 11. A revolver comprising: a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having a plurality of chambers, each of the plurality of chambers adapted to receive a cartridge, wherein the cylinder is rotatable into discrete firing positions; and a pawl connected to the hammer for rotating the cylinder thirty degrees between the discrete firing positions.
 12. The revolver of claim 11, wherein the pawl has a single finger adapted to contact the cylinder.
 13. The revolver of claim 11, wherein the pawl is adapted to contact the cylinder at only a single point during rotation of the cylinder.
 14. The revolver of claim 11, further comprising a ratchet on the cylinder, wherein the pawl engages the ratchet to rotate the cylinder.
 15. The revolver of claim 14, wherein the ratchet comprises a plurality of teeth and wherein the pawl is adapted to engage only a single tooth of the plurality of teeth to rotate the cylinder between discrete firing positions.
 16. The revolver of claim 11, wherein the frame has an aperture and wherein one of the plurality of chambers is aligned with the aperture in the discrete firing position.
 17. The revolver of claim 11, wherein each of the plurality of chambers is adapted to receive a .22 caliber cartridge.
 18. A revolver comprising: a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having more than six chambers, each of the more than six chambers adapted to receive a cartridge, wherein the cylinder is rotatable into a plurality of discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the plurality of discrete firing positions, wherein the pawl has a single finger adapted to contact the cylinder.
 19. The revolver of claim 18, wherein the pawl is adapted to contact the cylinder at only a single point during rotation of the cylinder. 